В информатике это Массив
Во-первых в начале НЕ сin << sys, а сin >> s;
Во-вторых ты объявил/а все переменные в первом ифе, а значит в других функциях они уже не видны, поэтому стоит их объявить глобально
В-третьих переменная g не используется, поэтому можно ее и не объявлять
Вот код:
#include <iostream>
#include <cmath>
using namespace std;
int main() {
int sys;
float a, b, c, d, e, sum, mid, pi=3.14, r;
cout << "if you would midle write-1, if place of circle-2" << endl;
cin >> sys;
if(sys == 1) {
cout << "input first midle" << endl;
cin >> a;
cout << "inpur second midle" << endl;
cin >> b;
cout << "input third midle" << endl;
cin >> c;
cout << "input thord midle" << endl;
cin >> d;
cout << "input fived midle" << endl;
cin >> e;
sum = a + b + c + d + e;
mid = sum / 5;
cout << "your midle: ";
cout << mid;
}
else{
if(sys == 2) {
cout << "this is the circle area formula S=pi*r^2" << endl;
cout << "input radius(r)" << endl;
cin >> r;
cout << pi * r * r;
}
}
return 0;
}
С++20
#include <iostream>#include <vector>class Point {public: int x, y; Point() = default; Point(const Point &) = default; Point(int _x, int _y) : x(_x), y(_y) {} Point operator + (const Point& p) const { return Point {x + p.x, y + p.y}; } Point operator - (const Point& p) const { return Point {x - p.x, y - p.y}; } std::vector<Point> operator & (const Point& p) const { return std::vector<Point> { Point {x + p.x, y + p.y}, Point {x - p.x, y + p.y}, Point {x + p.x, y - p.y}, Point {x - p.x, y - p.y}, Point {x + p.y, y + p.x}, Point {x - p.y, y + p.x}, Point {x + p.y, y - p.x}, Point {x - p.y, y - p.x}, }; } static Point max (const Point& p1, const Point& p2) { return Point {std::max(p1.x, p2.x), std::max(p1.y, p2.y)}; } static Point min (const Point& p1, const Point& p2) { return Point {std::min(p1.x, p2.x), std::min(p1.y, p2.y)}; } [[nodiscard]] int distance_to_by_ch (const Point & p) const { return std::max(std::abs(p.x - x), std::abs(p.y - y)); } [[nodiscard]] int distance_to_by_m (const Point & p) const { return std::abs(p.x - x) + std::abs(p.y - y); } friend std::ostream &operator << (std::ostream &os, Point const &p) { return os << "(" << p.x << ";" << p.y << ")"; } Point & operator = (const Point &) = default; bool operator == (const Point & p) const { return x == p.x && y == p.y; }};class Horse {public: const Point p; explicit Horse (const Point position) : p(position) { } [[nodiscard]] bool can_I_kill_this_guy (const Point & m) const { auto field = p & Point{2, 3}; return std::find(field.begin(), field.end(), m) != field.end(); }};std::istream &to_number(std::istream &stream) { char ch; do { ch = stream.get(); } while (!isalpha(ch)); if (isupper(ch)) ch -= 16; else ch -= 48; stream.putback(ch); return stream;}int main () { Point horse_p{}, stranger_p{}; std::cin >> horse_p.x >> to_number >> horse_p.y; std::cin >> stranger_p.x >> to_number >> stranger_p.y; Horse jack(horse_p); std::cout << "I am a Horse placed on " << jack.p << ". " << "Can I kill those guy on " << stranger_p << "? " << "-> " << std::boolalpha << jack.can_I_kill_this_guy(stranger_p); }
Массив
Объяснение: